Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757613Ab2BIJ7q (ORCPT ); Thu, 9 Feb 2012 04:59:46 -0500 Received: from mga03.intel.com ([143.182.124.21]:52699 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757426Ab2BIJ7o (ORCPT ); Thu, 9 Feb 2012 04:59:44 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="104851088" Date: Thu, 9 Feb 2012 17:49:38 +0800 From: Wu Fengguang To: Damien Wyart Cc: Shaohua Li , Andrew Morton , linux-fsdevel@vger.kernel.org, LKML , Jens Axboe Subject: Re: [PATCH] block: remove plugging at buffered write time Message-ID: <20120209094938.GA5403@localhost> References: <20120208110143.GA5550@localhost> <1328750089.5949.1.camel@sli10-conroe> <20120209080726.GB28465@localhost> <20120209092535.GA10272@brouette> <20120209094019.GA516@brouette> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120209094019.GA516@brouette> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4687 Lines: 136 On Thu, Feb 09, 2012 at 10:40:19AM +0100, Damien Wyart wrote: > > > Done, thanks! Here is the updated patch with O_SYNC write fix. > > > Got these errors with the updated patch on top of 3.3-rc3: > > > fs/sync.c: In function 'vfs_fsync_range': > > fs/sync.c:167:18: error: storage size of 'plug' isn't known > > fs/sync.c:173:2: error: implicit declaration of function 'blk_start_plug' [-Werror=implicit-function-declaration] > > fs/sync.c:175:2: error: implicit declaration of function 'blk_finish_plug' [-Werror=implicit-function-declaration] > > fs/sync.c:167:18: warning: unused variable 'plug' [-Wunused-variable] > > Adding a #include at the top of fs/sync.c solved the > problem. Of course, this needs approval of a kernel developper before > being added to the patch and resubmitted because I know adding #includes > can have unwanted consequences sometimes or be seen as bloat... Thank you! This includes the necessary blkdev.h and it compiles here too: Subject: block: remove plugging at buffered write time Date: Tue Jan 31 18:25:48 CST 2012 Buffered write(2) is not directly tied to IO, so it's not suitable to handle plug in generic_file_aio_write(). Also moves unplugging to lower layers: - for direct I/O, from around ->direct_IO() to do_blockdev_direct_IO() - for O_SYNC writes, to around ->fsync() CC: Jens Axboe CC: Li Shaohua Signed-off-by: Wu Fengguang --- fs/direct-io.c | 5 +++++ fs/sync.c | 11 ++++++++++- mm/filemap.c | 7 ------- 3 files changed, 15 insertions(+), 8 deletions(-) --- linux-next.orig/mm/filemap.c 2012-02-08 19:33:29.000000000 +0800 +++ linux-next/mm/filemap.c 2012-02-09 15:59:47.000000000 +0800 @@ -1421,12 +1421,8 @@ generic_file_aio_read(struct kiocb *iocb retval = filemap_write_and_wait_range(mapping, pos, pos + iov_length(iov, nr_segs) - 1); if (!retval) { - struct blk_plug plug; - - blk_start_plug(&plug); retval = mapping->a_ops->direct_IO(READ, iocb, iov, pos, nr_segs); - blk_finish_plug(&plug); } if (retval > 0) { *ppos = pos + retval; @@ -2610,13 +2606,11 @@ ssize_t generic_file_aio_write(struct ki { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; - struct blk_plug plug; ssize_t ret; BUG_ON(iocb->ki_pos != pos); mutex_lock(&inode->i_mutex); - blk_start_plug(&plug); ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos); mutex_unlock(&inode->i_mutex); @@ -2627,7 +2621,6 @@ ssize_t generic_file_aio_write(struct ki if (err < 0 && ret > 0) ret = err; } - blk_finish_plug(&plug); return ret; } EXPORT_SYMBOL(generic_file_aio_write); --- linux-next.orig/fs/direct-io.c 2012-02-08 19:33:29.000000000 +0800 +++ linux-next/fs/direct-io.c 2012-02-09 16:03:04.000000000 +0800 @@ -1106,6 +1106,7 @@ do_blockdev_direct_IO(int rw, struct kio unsigned long user_addr; size_t bytes; struct buffer_head map_bh = { 0, }; + struct blk_plug plug; if (rw & WRITE) rw = WRITE_ODIRECT; @@ -1221,6 +1222,8 @@ do_blockdev_direct_IO(int rw, struct kio PAGE_SIZE - user_addr / PAGE_SIZE); } + blk_start_plug(&plug); + for (seg = 0; seg < nr_segs; seg++) { user_addr = (unsigned long)iov[seg].iov_base; sdio.size += bytes = iov[seg].iov_len; @@ -1279,6 +1282,8 @@ do_blockdev_direct_IO(int rw, struct kio if (sdio.bio) dio_bio_submit(dio, &sdio); + blk_finish_plug(&plug); + /* * It is possible that, we return short IO due to end of file. * In that case, we need to release all the pages we got hold on. --- linux-next.orig/fs/sync.c 2012-02-09 15:59:52.000000000 +0800 +++ linux-next/fs/sync.c 2012-02-09 17:39:02.000000000 +0800 @@ -15,6 +15,7 @@ #include #include #include +#include #include "internal.h" #define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \ @@ -164,9 +165,17 @@ SYSCALL_DEFINE1(syncfs, int, fd) */ int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync) { + struct blk_plug plug; + int ret; + if (!file->f_op || !file->f_op->fsync) return -EINVAL; - return file->f_op->fsync(file, start, end, datasync); + + blk_start_plug(&plug); + ret = file->f_op->fsync(file, start, end, datasync); + blk_finish_plug(&plug); + + return ret; } EXPORT_SYMBOL(vfs_fsync_range); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/